Fig. 1. Identification of the med-6 mutation. (A) The physical and genetic
maps of the med-6 region. The yeast artificial chromosome (YAC)
Y57E12 contained the med-6 gene. The cosmid gap within the YAC is
indicated. The genetic deficiencies, sDf20 and sDf30, delete both
unc-68 and odr-2, whereas the deficiency, nDf32,
does not. Lethal mutations, let-322, let-339, let-343, let-404, let425,
let-438 and let-468, which were mapped in that region, are
shown. The map is not drawn to an exact scale. (B) Genomic structure of
med-6 and the mutation identified in let-425. The
med-6 gene contains three exons separated by two introns. The
med-6 gene isolated from the homozygous let-425 animals
contained a point mutation that changes C to T, causing a change in the amino
acid residue from Arg to a stop codon. The numbers above the genomic structure
are the amino acid numbers encoded by the gene.
